The proposed three-year project will assess the effects of mainstreaming on the behaviors of mentally retarded children in integrated classrooms. The class of behaviors related to social interaction will receive primary emphasis. Of particular interest is the effects of social interaction on other areas of the children's lives such as academic achievement and self-esteem. The project will investigate these concomitant tissues in detail. In addition, the project will develop an evaluate a behavioral treatment package designed to increase the quality and quantity of interactions occurring in mainstreamed setting. Experimental intervention will occur in two additional mainstreamed classrooms. The treatment will utilize instructional techniques including modeling, role-playing, and reinforcement based procedures. A multiple-baseline experimental design across subjects and classrooms will be used to evaluate and establish the reliability of the treatment package. Further efforts will be directed at the establishment of reliable techniques to increase generalization and maintenance of treatment effects on settings outside of the training locale. The second and third project years will center on the development of methods to train existing school staff in the effective use of the training procedures developed in year one. Finally, a self-contained and fully exportable package program composed of both a classroom-based training kit and a teacher training instructional program will be developed. A comprehensive evaluation plan for all phases of the project is included.